Vacuum pack bag and sealing package therefor



A ril 23, 1963 T. E. PIAZZE 3,086,693

VACUUM PACK BAG AND SEALING PACKAGE THEREFOR Filed June 11, 1958 2 Sheets-Sheet 1 INVENTOR 1 720: aaZ P212 zze Aprll 23, 1963 1'. E. PIAZZE 3,036,693

VACUUM PACK BAG AND SEALING PACKAGE THEREFOR Filed June 11, 1958 v 2 Sheets-Sheet 2 IMF-.5-

INVEN 1 OR momasflfi'azze ATTORNEYS In thepackagingfof cheeses; meats; celfeeaiid various other communes-ac s quite omm-bans mum-pac them infsealedf'bagsf of polyethylene or o'the 'r heat-scab able plastic, but difiiculti'e's have'b e' experienced v in vacuumizin'gthe filled bags and then tightly" sealing them against re-entrance of'air.

n has been prepo's edto provideonejwall of in}: bag

flexible patch as 'to' prevent distortion 'of thispat l during;

performance or the heat-sealing opera n; there is nger of producing a-fau1t9 s a1. Als ,wIteii'vacuum-Pack'agE in'g a rather finely granulated o'r' a"-powderedmaterial, there has been liability of some of such" m'j "rial be} com entrained with the outgoingt; andjbecoming' deposited onthe 1 surfaces of the bag wall and patch which are to be: heat-sealed tqgethe'r, and: such deposits have interferedwith the production of a"perfec't seal; v V. Y The present invention has aimed to overcome the above mentioned difficulties.

In carrying out the' above end; aspecific objectha's been'to provide an im' 'iro'ved patch comprising a rela tively stiff backing'sheet and a film of heat-scalable material secured to the side of said backing she'etwhich faces the bag wall having the air-evacuating opening. The relatively stiff backing sheet is exposed to'th e' bag contents and therefore, even if such contents do not contact smoothly and uniformly with the patch, appreciable patch distortion'will be prevented;v Consequently, when a heated sealing member is pressed against the bag wall to seal it to the patch film; saidba'g wall and film will become tightly. clamped between'the' relatively stiif patch backing and said sealing member, and a perfect seal will beproduce'd. v

Another specific object hasb'een to seal all' edges of the patch to the bag wall and to admit air to theevacuating passage between the patch and the bag wall, only through perforations inthe patch. Thus, by forming these perforations so fine that particles ofigranu'lated or' powdered bag contentscannot pass throughthem, such particles willbe excluded froni'the opposed surfaces of said patch and M wall and cannot interfere with heat sealing.

'With' the above arid other objc'cts'in' view that will hereinafter appear, the nature of the invention will be more clearly reference to the following tron, the a'p'p ehd e'd' claims and the sev- 'd iiithe' a'cc'on'ipa'iiying drawings. In the drawirigs'i FIGURE 1 is a sat-- clean e, partly broken away,

filled with granular material aid-sir readiness tor the evacuation of air through, the perforations in the" patch.

FIGURE 2 is" a veftical' sectional view, partly in elevation, showing the filled ba'g eriga 'ie d'with the air-evacuatover said opening and spaced from; said" showing a bag' having a perfo'rat'edpateh, the bag being a Patented Apr. 23; 1963- 1 of togeth'e'r the portions of the bag walls and around the" air evacuatin'g' opening" and between thlS, opening and the" patehp'erforations;

FIGURE 4 is a mgmma *topfview'showin'g' the bagsupport, the air-evacuating'member and 'the"heat-sealing FIGURE 5 is a view similar to FIGURE 1 but showing acenstruction which may be employed when there isn'o danger of any particles of the bag contents entering I betw'centhepatch and bag wall.

The bag' 10"shown 'in' the drawings is constructed from two sheets'lland 12 of plastic heat-scalable stock, three edges of said sheets'b'eing heat-sealed together at' the factory, as indicated at'13,' leaving the bag open at 'o'ne end fo'r'fillin'g; The open end is'to be heat-sealedat14, after filling. This type of bag'has been shown for illustrative purposes only and other known bag structures could be employed if desired.

The sheet" 11' forms one side wall of'the bagandis formed w'ith'an air-evacuating'bpening 15'. Within the bag is a patch 16fwhichextends across the opening15 and issecuredtotthc' bag' wall 11. Provision is made for spacingthepatch'IG- from the wall 11' to provide an airevacu'atin'g passage 17 between them, said passage being in communication with the opening-15 and with the bag interior;

In each form of the'invention, the patch le is of composite forman'd-comprises a' relatively stitf backing sheet 18;arid"a film 19 secured to theside of said backing sheet 18 which faces hebagwm -11. The relatively stiif backing sheet 18 may be formed from cardboard or other appropriate material having required stiffnessto' prevent patch distortion during se'alin'g around the opening 15, The film 19' is of heat-scalable material, for example polyethylene, and it' may be cemented to or otherwise united with the relatively stiff backing sheet 18', or it may be formed by a layer of heat-scalable cement applied to said backing sheet. In either instance, the film 19 preferably has a'multiplicity'of suitable projections 20 which space the patch 16 from the bag wall 11 to provide the passage 17. However, this bag wall 11 could well be provided with equivalent spacing projections, if desired.

In FIGURES l to 3, all edges of the patch 16 are heat-sealed to the bag wall 11 as indicated at 21 and the passage 17 communicates with the bag interior only through perforations 22. These perforations 22 may be of any desired'shape and they are all radially spaced from the opening 15. While they are shown as disposed in a circular series, this is not essential. All air being evacuated from the bag (see FIGURE 2) flows through the perforations 22 to the passage 17 to and through the opening 15. Therefore, by' forming the perforations 22 sufiiciently small to prevent granular or powdered bag contents C from passing through them, particles of such contents cannot become deposited on the opposed surfaces of the patch film 19 and bag wall 11 and cannot therefore interfere with heat sealin'g'of these elements together after air evacuation. y

when the bag contents are to be such that there is no danger of any particles thereof entering the passage 17, all edges of the composite patch 16 need not be sealed to the bag wall 11 and said patch need not have the perforations 22'. Such a construction is shown in FIGURE 5 andthe contents are indicated at C'. In this view, two edges or the patch 16 are shown heat-sealed at 21" to the bagWall 11. The heat sealing 21' is shown in stripe form but could well be at intervals only.

The apparatus disclosed in FIGURES 2, 3 and 4 is preferably employed in effecting air evacuation from the bag and in then sealing the latter against re-entrance of air. In these views a horizontal table 23 is shown, upon which to lay the filled bag. This table 23 has an opening 24 into which the upper end of an air-evacuating pipe 25 extends, the table and pipe being fixedly mounted in any suitable way. The upper extremity of the pipe 25 is preferably in the same plane with the top of the table 23, is open, and is of a diameter less than that of the table opening 24 but greater than that of the bag opening 15. A normally lowered sealing ring 26 surrounds the pipe 25 and may be raised by any suitable means. This ring 26 is heated by flame from a suitable manner, to a temperature at which it may be utilized to heat-seal the bag wall 11 to the patch film 19 after evacuation of air from the bag 10.

The filled bag is laid upon the table 23 as seen in FIG- URE 2, with its side wall 11 resting on the upper end of the pipe 25 and with the opening 15 communicating with said pipe. Then by any adequate pump means, partial vacuum is created in the pipe 25. This causes the bagcontained air to enter the passage 17, flow through this passage to the opening 15 and flow through this opening to and through the pipe 25. When the patch of FIG- URES 1 to 3 is used, the air from the bag enters the passage 17 only through the perforations 22. When the patch of FIGURE is employed the air enters the passage :17 at the periphery of said patch. When the desired vacuumizing has been attained, the heated sealing ring 26 is raised as seen in FIGURE 3. This causes tight clamping of the bag wall 11 and the patch film 19 between the sealing ring 25 and the stiff patch backing 18 and the heat from said sealing ring heat-seals said wall 11 and filrri 19 together as seen at 28. As the patch backing 18 prevents distortion of the patch film 19, even if the bag contents do not smoothly and uniformly conburner 27, or in any other tact with said backing, a perfect seal is assured. When the patch of FIGURES l to 3 is employed, the seal 28 is, of course, between the opening 15 and the perforations 22. Regardless of which form of patch is used, the projections 20 in the zone of the seal 28 do not interfere with the formation of said seal, as they become sufliciently fluid to flatten out into the plane of the film 19.

During the air-evacuating and heat-sealing operations, a bag hold-down plate 29 may be employed if the weight of the bag contents be insufficient to properly hold the bag down when the sealing ring 26 is raised.

From the foregoing, it will be seen that novel and advantageous provision has been disclosed for attaining the desired ends. However, variations may well be made within the scope of the invention as claimed, and it is to be understood that the invention is not restricted to a bag but is adaptable also to'other forms of containers, whether flexible throughout or flexible only at the wall portion which is to be sealed to the patch.

I claim:

1. A container having a flexible heat-scalable wall to externally abut an air-evacuating member, said flexible wall having an air-evacuating opening for communication with said air-evacuating member, and a patch secured to the inner side of said flexible wall and extending over said air-evacuating opening, the major portion of said patch being spaced from said flexible wall to provide an air-evacuating passage between them, said patch comprising a relatively stiff backing sheet and a film of heatsealable material secured to the side of said relatively stifi backing sheet toward said flexible wall, said relatively stifi backing sheet being formed of a material other than heat-scalable material and the other side of said relatively stiff backing sheet being exposed to the container contents; whereby when a heat-sealing member is externally pressed against saidflexible wall around said air-evacuating opening to heat-seal this wall and said film together, said wall and film will be clamped between said relatively 4 stiff backing sheet and the heat-sealing member to assure a tight seal, said film being provided with a multiplicity of projections abutting said flexible wall and spacing this wall from said patch to provide said air-evacuating passage.

2. A structure as specified in claim 1, in which all edges of said patch are sealed to said flexible wall, said patch being provided with air-evacuating perforations placing the interior of the container in communication with said air-evacuating passage, said perforations being all spacedradially from said air-evacuating opening to permit heatsealing between this opening and said perforations.

3. A structure as specified in claim 1, in which an edge portion of said film is free of attachment to said flexible wall to admit air to said air-evacuating passage.

4. A container having a flexible heat-scalable wall to externally abut an air-evacuating member, said flexible wall having an air-evacuating opening for communication with said air-evacuating member, and a patch secured to the inner side of said flexible wall and extending over said air-evacuating opening, the major portion of said patch being spaced from said flexible wall to provide an airevacuating passage between them, said patch comprising a relatively stiff backing sheet and a film of heat-scalable material secured to the side of said relatively stiff backing sheet toward said flexible wall, said relatively stiff backing sheet being formed of a material other than heat-sealable material and the other side of said relatively stiff backing sheet being exposed to the container contents; whereby when a heat-sealing member is externally pressed against said flexible wall around said air-evacuating opening to heat-seal this wall and said film together, said wall and film will be clamped between said relatively stifi backing sheet and the heat-sealing member to assure a tight seal, all edges of said patch being sealed to said flexible wall, said patch being provided with air-evacuating perforations placing the interior of the container in communication with said air-evacuating passage, said perforations being all spaced radially from said airevacuating opening to permit heat-sealing between this opening and said perforations, said film being'provided with a multiplicity of projections abutting said flexible wall and spacing this wall from said patch to provide said air-evacuating passage.

5. A sealing patch comprising a relatively stiff backing sheet formed of a material other than heat-scalable material, and a film of heat-scalable material secured to one side of said relatively stifl backing sheet, said patch having a multiplicity of projections for spacing said film slightly from the inner side of a flexible container wall.

6. The patch of claim 5, in which said patch is provided with air-evacuating perforations which extend through said relatively stifi'backing sheet and through said film, said perforations being radially spaced from the central zone of the patch.

7. The patch of claim 5, in which said patch is particularly intended for use in a hollow container and is provided with airevacuating perforations which extend through said relatively stiff backing sheet and through said film, said perforations being radially spaced from the central zone of the patch and being so small as to permit passage of air therethrough while obstructing passage therethrough of any fill from the interior of the container.

8. A container having a flexible heat-sealable wall to externally abut an air-evacuating member, said flexible wall having an air-evacuating opening for communication with said air-evacuating member, and a patch secured to the inner side of said flexible wall and extending over said air-evacuating opening, the major portion of said patch being spaced from said flexible wall to provide an airevacuating passage between them, said patch comprising a relatively stiff backing sheet and a film of heat-sealable material secured to the side of said relatively stiff backing sheet toward said flexible wall, said relatively stiff backing sheet being formed of a material other than heat-scalable material and the other side of said relatively stitt backing sheet being exposed to the container contents; whereby when a heat-sealing member is externally pressed against said flexible wall around said air-evacuating opening to heat-seal this wall and said film together, said wall and film will be clamped between said relatively stiff backing sheet and the heat-sealing member to assure a tight seal, all edges of said patch being sealed to said flexible wall, said patch being provided with air-evacuating perforations placing the interior of the container in communication with said air-evacuating passage, said perforations being all spaced radially from said air-evacuating opening to permit heat-sealing between this opening and said perforations and being so small as to permit passage of air therethrough while obstructnig passage therethrough of any fill from the interior of the container.

9. A container having a flexible heat-scalable wall to externally abut an air-evacuating member, said flexible wall having an air-evacuating opening for communication with said air-evacuating member, and a patch secured to the inner side of said flexible wall and extending over said air-evacuating opening, the major portion of said patch being spaced from said flexible wall to provide an airevacuating passage between them, said patch comprising a relatively stilt backing sheet and a film of heat-scalable material secured to the side of said relatively stiff backing sheet toward said flexible wall, said relatively stilt backing sheet being formed of a material other than heat-scalable material and the other side of said relatively stifi backing sheet being exposed to the container contents; whereby when a heat-sealing member is externally pressed against said flexible wall around said air-evacuating opening to heat-seal this wall and said film together, said wall and film will be clamped between said relatively stiff backing sheet and the heat-sealing member to assure a tight seal,

all edges of said patch being sealed to said flexible wall,

References Cited in the file of this patent UNITED STATES PATENTS 2,330,015 Stokes Sept. 21, 1943 2,554,157 Snyder May 22, 1951 2,714,557 Mahaify Aug. 2, 1955 2,740,570 Breadner Apr. 3, 1956 2,778,173 Taunton Jan. 22, 1957 2,821,338 Metzger Jan. 28, 1958 2,840,961 Karpowicz July 1, 1958 2,870,954 Kulesza Ian. 27, 1959 

4. A CONTAINER HAVING A FLEXIBLE HEAT-SEALABLE WALL TO EXTERNALLY ABUT AN AIR-EVACUATING MEMBER, SAID FLEXIBLE WALL HAVING AN AIR-EVACUATING OPENING FOR COMMUNICATION WITH SAID AIR-EVACUATING MEMBER, AND A PATCH SECURED TO THE INNER SIDE OF SAID FLEXIBLE WALL AND EXTENDING OVER SAID AIR-EVACUATING OPENING, THE MAJOR PORTION OF SAID PATCH BEING SPACED FROM SAID FLEXIBLE WALL TO PROVIDE AN AIREVACUATING PASSAGE BETWEEN THEM, SAID PATCH COMPRISING A RELATIVELY STIFF BACKING SHEET AND A FILM OF HEAT-SEALABLE MATERIAL SECURED TO THE SIDE OF SAID RELATIVELY STIFF BACKING SHEET TOWARD SAID FLEXIBLE WALL, SAID RELATIVELY STIFF BACKING SHEET BEING FORMED OF A MATERIAL OTHER THAN HEAT-SEALABLE MATERIAL AND THE OTHER SIDE OF SAID RELATIVELY STIFF BACKING SHEET BEING EXPOSED TO THE CONTAINER CONTENTS; WHEREBY WHEN A HEAT-SEALING MEMBER IS EXTERNALLY PRESSED AGAINST SAID FLEXIBLE WALL AROUND SAID AIR-EVACUATING OPENING TO HEAT-SEAL THIS WALL AND SAID FILM TOGETHER, SAID WALL AND FILM WILL BE CLAMPED BETWEEN SAID RELATIVELY STIFF BACKING SHEET AND THE HEAT-SEALING MEMBER TO ASSURE A TIGHT SEAL, ALL EDGES OF SAID PATCH BEING SEALED TO SAID FLEXIBLE WALL, SAID PATCH BEING PROVIDED WITH AIR-EVACUATING PERFORATIONS PLACING THE INTERIOR OF THE CONTAINER IN COMMUNICATION WITH SAID AIR-EVACUATING PASSAGE, SAID PERFORATIONS BEING ALL SPACED RADIALLY FROM SAID AIR-EVACUATING OPENING TO PERMIT HEAT-SEALING BETWEEN THIS OPENING AND SAID PERFORATIONS, SAID FILM BEING PROVIDED WITH A MULTIPLICITY OF PROJECTIONS ABUTTING SAID FLEXIBLE WALL AND SPACING THIS WALL FROM SAID PATCH TO PROVIDE SAID AIR-EVACUATING PASSAGE. 